Sorry ! another quick question about stones.

[newstart]

Recently I have been sieving off stones from my loam potting soil which are around 10-20mm sometimes more. I wondered  to save money if I could use these instead of mixing chippings when planting alpines in the soil. It must add some drainage but would it be to much of an obstruction for the roots etc. I am getting another 50 or so alpines delivered soon so rather than keep wondering about it I thought I'd ask. My father who is also an avid gardener would make sure to remove all stones from the soil. Whether this gave more ability for root contact to the soil itself I am not sure of his reasons.

Thanks very much indeed.

[Darren]

Hi David - the simple answer is yes, go ahead and use them. I always felt that the removal of every stone from ordinary garden soil was a total waste of effort unless you are growing root veg like carrots and don't want them forking. I sieve my old potting soil at repotting time and re-use the chippings in the alpine garden or bulb frame.

[ranunculus]

Hi David,
Might I suggest that you take your obviously avid interest in these beautiful alpine plants a stage further by trying to visit the mountain areas where they grow?  You will be utterly amazed by the 'composts' that support some of these hardy gems ... they grow in shale, detritus, scree, rock slabs, crevices, cliffs and boulders ... soil sieved of stones and pebbles would be anathema to them.

[newstart]

There natural surroundings in the mountains would as you say contain stones as part of the soil. Does this mean that this is as good as or not so good as using chippings with the smaller size. Sorry if I labour the point a bit but I have always wondered. Obviously stones in a small 9cm pot is out of the question as it would impede root growth. Stones in the mountains or gardens should make it more free draining but I think not so much as if using chippings which allow more water through and possibly air. I am completely guessing of course and its true to say alpines as in the wild will adapt as long as an excess of stones don't case compaction.

Thanks.

[Lesley Cox]

Personally, I wouldn't ever bother sieving out stones of whatever size. They all help to give good drainage and roots do seem to be attracted towards stone, rocks or grit, just as they are towards the edge of a trough or a concrete path. I don't even mind my carrots with a fork in them.

[Diane Whitehead]

Plants grow wonderfully well in crevice gardens where they have rock
on each side of their roots.

But why not try an experiment?  Two of each plant, matched for size,
planted in two similar pots, one stony, and one stone-free.

Take pictures and show us how they do.

[newstart]

Thanks I'd assumed chippings were better, so to hear there is no impeding of root growth but just better drainage is useful with larger stones. Thats very helpful and I can save money now and use them instead of the expensive chippings. An experiment may be a great idea I will look into it thanks Diane. I must admit for some reason I get a little sceptical about the mountain areas having idealic conditions as when in those situations plants can often look a little less cared for. Having said that replicating soils and adding a bit more shelter in a garden then may solve this. And of course a seed often germinates in the mountain because the plant knows its in a crevice with more moisture for example. Then there are some plants I assume that will thrive in the open wind swept conditions and still look as healthy as a garden plant often because drainage is so good??-how many of those remain healthy in that situation may be aided by snow warmth covering in winter may be. I don't require answers neccesarily to this particualr post as its probably wrong to take up peoples time to much. If I need correction on what I've said and you feel inclined to share more about natural habitat thats great.

David.

[Katherine J]

I must admit for some reason I get a little sceptical about the mountain areas having idealic conditions as when in those situations plants can often look a little less cared for.

They look less cared for? 

I would let these pictures to speak instead of me.

Habitat on a rock wall
Ranunculus glacialis and Primula daonensis
This is the "compost" in which Ranunculus glacialis leaves: stone "chippings" of different size

[ranunculus]

Super images Kata ... of super plants!

[newstart]

Thanks katherine J lovely!

[gote]

I agree with what has been said above but would like to add a reminder.
In many of these alpine locations, where alpine plants grow in screes, there is abundant water from melting snow higher up and/or from water that is precipitated out of moist air when it is directed upwards by the mountain winds. The root run downwards to water containing layers is also fairly unretricted and many many times the depth of any pot.
If we are to grow our alpines in this extremely well draining and gritty soil we have to water a lot.

By the way It is true that roots tend to follow stones and this can be used to find the host plants of Pedicularis and other more or less parasitic plants.
Lifting stones arund a Pedicularis plant is likely to expose the contact points between it and its host.  Those of us who climb mountains could do some research there.
Cheers
Göte

PS
Pedicularis lapponica is feeding off Salix herbacea and its allies.

[Katherine J]

Lifting stones arund a Pedicularis plant is likely to expose the contact points between it and its host. 

What a good idea! Thank You, Göte!

[newstart]

Great useful indeed.

[gote]

I now look forward to a complete list of all Pedicularis host plants next year   
Göte